How to grow tomatoes without soil: A comprehensive guide

1. Choose varieties of tomatoes

Select tomato varieties that are well suited to hydroponic or above-ground cultivation. Indeterminate varieties, such as cherry tomatoes, Beefsteak or Roma, are popular choices. Make sure you choose disease-resistant varieties to minimise the risks.

2. Hydroponic systems

There are different hydroponic systems to choose from. The most common for growing tomatoes include:

Deep Water Culture (DWC): In this system, tomato plants are suspended in a nutrient-rich water solution, their roots being immersed.
Nutrient film technology (NTF): This system involves a continuous flow of nutrient solution on a narrow and inclined channel where the roots of tomato plants hang.
Drip system: Drip systems provide a controlled release of nutrient solution to plant root areas via a network of tubes and emitters.
3. 3. Choose a culture substrate

Although hydroponic systems do not use soil, they require a growing substrate to support plants and ensure their stability. Common choices include:

Coconut fibre
Perlite
Rock wool
Hydroton (expanded clay granules)
Select a substrate that retains moisture while allowing good ventilation and support for the roots.

4. Maintaining appropriate nutritional solutions

In hydroponic systems, essential nutrients are provided to plants via nutrient solutions. These solutions typically contain macronutrients such as nitrogen, phosphorus and potassium, as well as micronutrients. Monitor the pH level of the nutrient solution (usually between 5.5 and 6.5) and adjust it if necessary to ensure optimal nutrient absorption.

5. Providing adequate light

Tomatoes need a lot of light to thrive. If you grow them indoors, invest in high-quality LED culture lamps that provide the spectrum needed for plant growth. The recommended lighting cycle is usually from 14 to 16 hours per day.

6. Maintain appropriate temperature and humidity

Tomatoes thrive at temperatures between 70 and 75oF (21 and 24oC) during the day and slightly cooler at night. The humidity levels should be about 70% at the sowing stage and gradually decrease as the plants mature.

7. Size and support

As your tomato plants grow, they can become heavy. To provide good support, use lattices, tusks or tomato cages. Regularly prune your plants to remove the lower leaves and promote the growth of the upper fruit branches.

8. Pest and disease management

Although hydroponic systems reduce the risk of soil-borne pests and diseases, you should be careful. Keep your culture area clean, monitor common tomato pests and apply appropriate treatments if necessary.

9. Pollination

Tomato plants may require manual pollination in a hydroponic system, as the absence of wind and insects may hinder natural pollination. Gently shake the plants or use a small brush to transfer the pollen between the flowers.

10. Harvesting
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